private void AddStringSwitch(ref PathSplit psp, string value, string arg, ParseResult.Builder result)
{
CommandSwitch sw = FindSwitchIdentifiedBy(value);
if (sw == null)
{
throw new InvalidInput("Invalid switch: " + value);
}
if (arg != null)
{
if (sw.arity != Arity.NoneOrOne)
{
throw new InvalidInput($"Switch {value} has argument, which is not allowed for the given switch.");
}
result.AddSwitch(sw);
if ((sw.arity == Arity.One || sw.arity == Arity.NoneOrOne) && result.AlreadyHasArgumentForLastSwitch())
{
throw new InvalidInput($"Switch {value} can accept only one argument, but two are supplied.");
}
result.AddArgForLastSwitch(arg);
psp = PathSplit.Maybe;
}
else
{
switch (sw.arity)
{
case Arity.None: psp = PathSplit.Maybe; break;
case Arity.One: psp = PathSplit.NotForOne; break;
case Arity.NoneOrOne: psp = PathSplit.Maybe; break;
case Arity.Any: psp = PathSplit.Not; break;
default: throw new Termination("Should not reach this.");
}
result.AddSwitch(sw);
}
}
/// <summary>
/// Main parsing method
/// </summary>
/// <exception cref="Termination">Internal error</exception>
/// <exception cref="InvalidInput">Input was not valid according to parsing rules</exception>
public ParseResult Parse(string[] args)
{
var result = new ParseResult.Builder();
PathSplit psp = PathSplit.Maybe;
foreach (var arg in args)
{
switch (psp)
{
case PathSplit.Not:
case PathSplit.Maybe: {
var(argType, value, swArg) = GetArgType(arg);
if (argType == ArgType.Separator)
{
psp = PathSplit.Yes;
break;
}
else if (argType == ArgType.SingleCharSwitch)
{
AddSingleCharSwitch(ref psp, value, swArg, result);
break;
}
else if (argType == ArgType.StringSwitch)
{
AddStringSwitch(ref psp, value, swArg, result);
break;
}
else if (argType == ArgType.Path)
{
if (psp == PathSplit.Not)
{
result.AddArgForLastSwitch(value);
// psp remains .Not.
break;
}
else if (psp == PathSplit.Maybe)
{
result.AddPath(value);
psp = PathSplit.Yes;
break;
}
throw new Termination("Should never reach this.");
}
throw new Termination("Should never reach this.");
}
case PathSplit.NotForOne: {
var(argType, value, swArg) = GetArgType(arg);
if (argType != ArgType.Path)
{
throw new InvalidInput("Expected path but got a switch at " + arg);
}
var lastSwitch = result.GetLastSwitch();
if (lastSwitch.arity == Arity.One && result.AlreadyHasArgumentForLastSwitch())
{
throw new InvalidInput($"Switch {value} can accept only one argument, but two are supplied.");
}
psp = PathSplit.Maybe;
result.AddArgForLastSwitch(arg);
break;
}
case PathSplit.Yes: {
result.AddPath(arg);
break;
}
default: throw new Termination("Should never reach this.");
}
}
return(result.Build());
}
private void AddSingleCharSwitch(ref PathSplit psp, string value, string arg, ParseResult.Builder result)
{
// Add all but last with null arg
for (int i = 0; i < value.Length - 1; i++)
{
AddStringSwitch(ref psp, value[0].ToString(), null, result);
}
// Add last with actual arg
AddStringSwitch(ref psp, value[value.Length - 1].ToString(), arg, result);
}